Conventionally, a seat apparatus is known, which includes a seat slide mechanism for adjusting a position of a seat. The seat slide mechanism includes a lower rail serving as a vehicle rail fixed to a vehicle floor, and an upper rail fixed to the seat. The upper rail is movably supported by the lower rail. One of the known seat apparatuses is disclosed in JP2002-254966A. According to the disclosed seat apparatus, a lower rail includes a bottom wall portion and guide wall portions, which are integrally formed by means of roll forming or press forming. The guide wall portions are provided in a standing manner at both sides of the bottom wall portion in a width direction for guiding an upper rail.
Further, the lower rail is provided with a bracket at which the lower rail is fixed to the vehicle floor by means of a bolt. The bracket is provided for stably mounting the lower rail on the vehicle floor in accordance with a shape of the floor, and is provided for preventing a head of the fixing bolt from being protruded from the lower rail and interfered with the upper rail.
However, because the lower rail according to the disclosed seat apparatus requires the bracket, the number of operating members is increased and manufacturing cost of the seat apparatus is increased. Moreover, because a space for housing the head of the bolt is required between the bottom wall portion of the lower rail and a bottom wall portion of the bracket, the seat apparatus is occasionally getting larger.
In order to avoid an increase of the number of the operating members, the bottom wall portion may be integrally formed with, by means of drawing, an operating member shaped similar to the bracket at which the lower rail is fixed to the vehicle floor. However, with the configuration of the lower rail, which includes the bottom wall portion and the guide wall portion integrally formed with each other and includes a complicated shape in a cross-section, distortion is provoked if the above-mentioned process is applied to form the operating member shaped similar to the bracket at the bottom wall portion by means of drawing. Accordingly, an accuracy of the seat rail may occasionally be lowered.
Further, in a condition where the guide wall portion of the lower rail includes a shape, which is folded inwardly in a width direction thereof, a width of an opening of the rail may be narrowed. On this occasion, in order to avoid interference between the head of the bolt for fixing the lower rail to the vehicle floor and the guide wall portion, the width of the opening may be required to be wider, and the cross-section of the rail may thereby occasionally be getting larger. Accordingly, in a condition where the seat rail is mounted on the vehicle, because of an enlargement of the opening in the width direction, an appearance may occasionally be detracted. Further, a protector may be required in order to shut out a foreign object, and the manufacturing cost of the seat apparatus may thereby be increased.
A need thus exists for a vehicle rail and a vehicle seat apparatus which can be downsized in totality while restraining the increase of the number of the operating members.